Table 2.

MBL of dental implants between two groups at two time points. N1: nonsmoking patient NO.1; N2: nonsmoking patient NO.2; N3: nonsmoking patient NO.3; N: the mean value of nonsmoking patient; S1: smoking patient NO.1; S2: smoking patient NO.2; S3: smoking patient NO.3; S: the mean value of smoking patient; MBL: marginal bone loss. P values were calculated from two-sided t-test.

Time (months)	N1	N2	N3	N (mean±SD)	S1	S2	S3	S (mean±SD)	P
6	0.85	0.89	0.72	0.80±0.039	1.58	1.77	1.83	1.73±0.075	<0.0001 (∗∗∗)
12	0.96	0.98	0.82	0.92±0.050	1.78	2.02	1.95	1.92±0.071	<0.0001 (∗∗∗)